Tissue implantation or grafting is a common surgical procedure in which tissue is transplanted from one area to another on a person's body, or from another person, without bringing its own blood supply. This is in contrast to flap surgery, in which the grafted tissue has an intact blood supply. The implanted tissue may be engineered, such as from stem cells and a collagenous scaffold. One important type of tissue engineering involves the formation of neural tissue, which is implanted to promote nerve regeneration and to repair damaged nerves. It is also possible to create implanted tissue via intravenous stem cell injections, through natural concentration of stem cells in affected regions.
Neural communication is required between the implanted tissue and existing tissue in order to allow sensory and functional information to be passed between the host tissue and implanted tissue. The implanted tissue generally contains nerve fibers that provide sensory or functional communication between the implanted tissue and the host. In many cases following the implantation procedure, however, neural communication between the implanted tissue and the existing tissue is limited or nonexistent, even though the implanted tissue is viable with a reasonable blood supply.
Currently, procedures used to improve neural communication with implanted tissue include peripheral nerve reconstruction, in which nerves are cut and re-approximated using very small sutures. Another option is bio-artificial nerve guidance conduits in order to guide axonal regrowth and connectivity. However, surgical procedures such as these are time consuming, highly invasive, and involve a long recovery period for the patient. It is apparent that a non-invasive approach would have significant benefits over existing technology.